Active noise cancellation (ANC) may be used to generate sound waves or anti-noise that destructively interferes with undesired sound waves. Potential sources of undesired noise may come from undesired voices, heating, ventilation, and air conditioning systems and other environment noise in a room listening space. Potential sources may also come from vehicle engine, tire interaction with the road and other environment noise in a vehicle cabin listening space. ANC systems may use feedforward and feedback structures, to adaptively formulate anti-noise signals. Sensors placed near the potential sources provide the reference signals for the feedforward structure. Sensors placed near the listeners' ear positions provide the error signals for the feedback structure. Once formulated, the destructively-interfering anti-noise sound waves may be produced through loudspeakers to combine with the undesired sound waves in an attempt to cancel the undesired noise. Combination of the anti-noise sound waves and the undesired sound waves can eliminate or minimize perception of the undesired sound waves by one or more listeners within a listening space.
Sound zones may be generated using speaker arrays and audio processing techniques providing acoustic isolation. Using such a system, different sound material may be delivered in different zones with limited interfering signals from adjacent sound zones. In order to realize the sound zones, a system may be designed using learning algorithm to adjust the response of multiple sound sources to approximate the desired sound field in the reproduction region.